Ancient Makistos or Samiko or Arini was built in a strategic position north of Kaiafas lake, boasting on the Samiko plain and the road that used to connect Pissatida with Trifylia and west Messenia in Antiquity.
Today, vestiges from the acropolis remain on the mountain Lapitha at an altitude of 200m, 2km from Kato Samiko village. The walls of the citadel enclose an almost triangular inclined area. Constructed with giant polygonal boulders, the walls are 2 meters thick and in some parts they are 5 meters tall. Impressive are the three openings that remain intact and whose construction is dated back to the 4th and 5th centuries. According to Herodotus, this is where the ancient city of Makistos stood, being a part of a six-city complex founded by Minyans in Trifylia of Elis.
The Mycenaean vestiges discovered were proved to belong to Arene, an ancient town in Elis. The Mycenaean tomb of Iardanus was discovered in Kleidi in 1954 and comprised 16 graves where a large number of funeral gifts of the period 1600-1200 BC were recovered. Near the tomb was the temple of Poseidon where vestiges of cyclopean masonry were discovered.
A roman bath and an Early Christianity church are north of the acropolis. There are also vestiges of a Turk castle, built by Ibrahim Pascha in 1826. The vestiges from the Mycenaean period show that Kleidi was a fortified city obviously due to its strategic position.